1. Field of the Invention
The present invention relates to an electrical feedthrough to be inserted into an opening of an implantable electrical treatment device. Such electrical treatment devices are, for example, implantable cardiac pacemakers, implantable cardioverters/defibrillators, or cochlear implants
2. Description of the Related Art
The electrical feedthrough has an electrically insulating insulation body, through which at least one electrically conductive terminal pin passes, which is connected to the insulation body hermetically sealed using a solder.
Electrical feedthroughs of this type are used for the purpose of producing an electrical connection between a hermetically sealed interior of a treatment device and the exterior of the treatment device. In known electrotherapy devices, such as cardiac pacemakers or cardioverters/defibrillators, a hermetically sealed metal housing is typically provided, which has a terminal body, also called a header, on one side, which carries terminal sockets for connecting electrode lines. The terminal sockets have electrical contacts which are used for the purpose of electrically connecting electrode lines to the control electronics in the interior of the housing of the cardiac pacemaker. A feedthrough, which is inserted hermetically sealed into a corresponding housing opening, is typically provided where the electrical connection enters the housing of the cardiac pacemaker.
Electrical feedthroughs of this type are frequently implemented as filter feedthroughs. In this case, the apparatuses carry an electrical filter, which is used for the purpose of short-circuiting external high-frequency electric interference, so that corresponding signals are fed, if at all, only strongly damped to the control electronics in the interior of the housing and the control electronics first experience interference at significantly greater signal strengths of the electrical interference than would be the case without the electrical filter. A filter of this type is typically formed by a filter body which is connected like a capacitor between a device ground and a particular electrical line passing through the feedthrough.
Such an electrical line passing through the feedthrough is typically formed by an electrically conductive terminal pin, which passes through a through opening in an electrically insulating insulation body. The electrically conductive terminal pin projects on both sides beyond the particular face of the insulation body, so that on both sides of the insulation body—and thus on both sides of the electrical feedthrough—continuing electrical lines may be connected to the terminal pin in each case—by soldering or welding, for example. A possible gap between a through opening in the insulation body, through which a particular terminal pin passes, and the terminal pin itself, is typically closed hermetically sealed using a solder, normally gold solder.
Manifold electrical feedthroughs of this type are known from the prior art. Examples may be found in U.S. Pat. No. 6,934,582, U.S. Pat. No. 6,822,845, U.S. Pat. No. 6,765,780, U.S. Pat. No. 6,643,903, U.S. Pat. No. 6,567,259, U.S. Pat. No. 6,768,629, U.S. Pat. No. 6,765,779, U.S. Pat. No. 6,566,978, and U.S. Pat. No. 6,529,103.
In spite of the manifold known feedthroughs, there is still the demand for improving them in regard to producibility and properties.